You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
141 lines
3.2 KiB
141 lines
3.2 KiB
/* |
|
* net/9p/util.c |
|
* |
|
* This file contains some helper functions |
|
* |
|
* Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net> |
|
* Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com> |
|
* Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov> |
|
* |
|
* This program is free software; you can redistribute it and/or modify |
|
* it under the terms of the GNU General Public License version 2 |
|
* as published by the Free Software Foundation. |
|
* |
|
* This program is distributed in the hope that it will be useful, |
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of |
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
|
* GNU General Public License for more details. |
|
* |
|
* You should have received a copy of the GNU General Public License |
|
* along with this program; if not, write to: |
|
* Free Software Foundation |
|
* 51 Franklin Street, Fifth Floor |
|
* Boston, MA 02111-1301 USA |
|
* |
|
*/ |
|
|
|
#include <linux/module.h> |
|
#include <linux/errno.h> |
|
#include <linux/fs.h> |
|
#include <linux/sched.h> |
|
#include <linux/parser.h> |
|
#include <linux/idr.h> |
|
#include <linux/slab.h> |
|
#include <net/9p/9p.h> |
|
|
|
/** |
|
* struct p9_idpool - per-connection accounting for tag idpool |
|
* @lock: protects the pool |
|
* @pool: idr to allocate tag id from |
|
* |
|
*/ |
|
|
|
struct p9_idpool { |
|
spinlock_t lock; |
|
struct idr pool; |
|
}; |
|
|
|
/** |
|
* p9_idpool_create - create a new per-connection id pool |
|
* |
|
*/ |
|
|
|
struct p9_idpool *p9_idpool_create(void) |
|
{ |
|
struct p9_idpool *p; |
|
|
|
p = kmalloc(sizeof(struct p9_idpool), GFP_KERNEL); |
|
if (!p) |
|
return ERR_PTR(-ENOMEM); |
|
|
|
spin_lock_init(&p->lock); |
|
idr_init(&p->pool); |
|
|
|
return p; |
|
} |
|
EXPORT_SYMBOL(p9_idpool_create); |
|
|
|
/** |
|
* p9_idpool_destroy - create a new per-connection id pool |
|
* @p: idpool to destroy |
|
*/ |
|
|
|
void p9_idpool_destroy(struct p9_idpool *p) |
|
{ |
|
idr_destroy(&p->pool); |
|
kfree(p); |
|
} |
|
EXPORT_SYMBOL(p9_idpool_destroy); |
|
|
|
/** |
|
* p9_idpool_get - allocate numeric id from pool |
|
* @p: pool to allocate from |
|
* |
|
* Bugs: This seems to be an awful generic function, should it be in idr.c with |
|
* the lock included in struct idr? |
|
*/ |
|
|
|
int p9_idpool_get(struct p9_idpool *p) |
|
{ |
|
int i; |
|
unsigned long flags; |
|
|
|
idr_preload(GFP_NOFS); |
|
spin_lock_irqsave(&p->lock, flags); |
|
|
|
/* no need to store exactly p, we just need something non-null */ |
|
i = idr_alloc(&p->pool, p, 0, 0, GFP_NOWAIT); |
|
|
|
spin_unlock_irqrestore(&p->lock, flags); |
|
idr_preload_end(); |
|
if (i < 0) |
|
return -1; |
|
|
|
p9_debug(P9_DEBUG_MUX, " id %d pool %p\n", i, p); |
|
return i; |
|
} |
|
EXPORT_SYMBOL(p9_idpool_get); |
|
|
|
/** |
|
* p9_idpool_put - release numeric id from pool |
|
* @id: numeric id which is being released |
|
* @p: pool to release id into |
|
* |
|
* Bugs: This seems to be an awful generic function, should it be in idr.c with |
|
* the lock included in struct idr? |
|
*/ |
|
|
|
void p9_idpool_put(int id, struct p9_idpool *p) |
|
{ |
|
unsigned long flags; |
|
|
|
p9_debug(P9_DEBUG_MUX, " id %d pool %p\n", id, p); |
|
|
|
spin_lock_irqsave(&p->lock, flags); |
|
idr_remove(&p->pool, id); |
|
spin_unlock_irqrestore(&p->lock, flags); |
|
} |
|
EXPORT_SYMBOL(p9_idpool_put); |
|
|
|
/** |
|
* p9_idpool_check - check if the specified id is available |
|
* @id: id to check |
|
* @p: pool to check |
|
*/ |
|
|
|
int p9_idpool_check(int id, struct p9_idpool *p) |
|
{ |
|
return idr_find(&p->pool, id) != NULL; |
|
} |
|
EXPORT_SYMBOL(p9_idpool_check); |
|
|
|
|